package org.example;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import org.example.handlers.EchoClientHandler;

import java.net.InetSocketAddress;

public class EchoClient {
    private final String host;
    private final int port;

    public EchoClient(String host, int port){
        this.host=host;
        this.port=port;
    }
    public static void main(String[] args) throws InterruptedException {
//        if(args.length!=2){
//            System.err.println("Usage: "+EchoClient.class.getSimpleName()+" <host> <port>");
//            return;
//        }
        String host = "localhost";//args[0];
        int port = 8880;//Integer.parseInt(args[1]);
        new EchoClient(host,port).start();
    }

    private void start() throws InterruptedException {
        EventLoopGroup group = new NioEventLoopGroup();
        try{
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioSocketChannel.class)
                    .remoteAddress(new InetSocketAddress(host,port))
                    .handler(new ChannelInitializer<SocketChannel>() {
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline().addLast(new EchoClientHandler());
                        }
                    });
            ChannelFuture f = b.connect();//这个地方会调用java.nio的selector.register和socketChannel.connect方法
                    f.sync();
            f.channel().closeFuture().sync();
        }finally {
            group.shutdownGracefully().sync();
        }
    }
}
